The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingFront airbag sensor lh circuit malfunction
Description
The front airbag sensor lh consists of the diagnostic circuit, the frontal
deceleration sensor, etc.
If the center airbag sensor receives signals from the frontal deceleration
sensor, it determines whether or
not the srs should be activated.
Dtc b1615/14 is recorded when a ma ...
Removal (2006/01- )
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove roof headlining assembly
Remove the roof headlining (see page ir ...
Wiper switch
Precaution
Precaution for vehicle with srs
Some procedures in this section may affect the
supplemental restraint system (srs). Prior to
performing the procedures, read the srs section's
"precaution" (see page ss-2).
Components
Removal
Disconnect cable from negat ...